Mizuno JPX921 Hot Metal Pro Irons Review

50 Words or Less

The Mizuno JPX921 Hot Metal Pro irons are game improvement irons with plenty of ball speed but little offset.  A rare combination that can be great for combo sets.

Introduction

For the last couple years, I’ve been critical of Mizuno for releasing too many irons that aren’t clearly differentiated.  The biggest exception has been the Hot Metal Pro, which I praised when it was unveiled in 2018.  Does the latest version continue to offer golfers something they can’t find anywhere else?

Check out the new Mizuno JPX923 Hot Metal Pro irons HERE

Looks

The Mizuno JPX921 Hot Metal Pro irons are game improvement irons without the offset.  The top line is thinner than expected, and the use of two tones of silver makes it appear even slimmer.  Offset and blade length are the two ways that the Pro model differentiates itself from the standard Hot Metal irons.

In the bag, the JPX921 Hot Metal Pro is nearly identical to the standard Hot Metal.  Both use a black and silver color scheme, eschewing any fancy paint fill colors.  The branding is confined to the cavity and looks sharp.

Sound & Feel

My primary issue with the original Hot Metal Pro irons [review HERE] was the unpleasant feel.  This is been improved markedly in the new version.

Both the JPX921 Hot Metal and the JPX921 Hot Metal Pro irons are made with the same Chromoly metal and feature a frighteningly thin face.  These irons feel very crisp on center but are much quieter than previous iterations.  Neither iron feels soft, but pure strikes do feel solid.

Feedback is about what you’d expect from a game improvement iron.  Misses get dull, losing the crisp snap.  Through the hands, feedback isn’t precise but it’s good enough to get a general idea about how you struck the ball.

Performance

What made the original Hot Metal Pro irons so intriguing was the combination of limited offset with forgiveness and ball speed.  That combination is still the main selling point with the JPX921 Hot Metal Pro irons.

On center, these irons are about as fast as anything you can buy.  The Chromoly face is extremely thin which leads to very high ball speeds.  Mizuno is also using a seamless cup face on these irons which helps to retain more ball speed on mishits.  I found that the forgiveness is good, but it’s not a club I would recommend for the higher handicap player.

The JPX921 Hot Metal and Hot Metal Pro have fairly strong lofts which are a key part of how they create so much distance and ball speed.  Strong lofts also lead to lower launch and lower spin.  I found the Hot Metal Pro to be slightly lower launching and spinning than the standard version.  As always, it is critical to be fit for these irons so you can hit the ball a long way and have it hold the green.

Conclusion

Whether you order a full set or just use them to fill out the top end of your bag, the Mizuno JPX921 Hot Metal Pro irons are going to help you hit the ball a long way.  The smaller head and reduced offset give them a look that’s more attractive to better players and makes them ideal for pairing with the JPX921 Forged or Tour.

Mizuno JPX921 Hot Metal Pro Irons Price & Specs

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Matt Saternus

Founder, Editor In Chief at PluggedInGolf.com
Matt is the Founder and Editor in Chief of Plugged In Golf. He's worked in nearly every job in the golf industry from club fitting to instruction to writing and speaking. Matt lives in the northwest suburbs of Chicago with his wife and two daughters.

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65 Comments

  1. My issue with thin faces is they almost seem to give you a diminished return on ball speed the faster you swing. Help slower speeds get higher speed but higher speed seems to overpower the thin face. For instance with the sub70 699 pro vs pxg gen 3 p the sub 70 was almost a full club longer with identical specs and same strike pattern. My 5 iron carry is 210. Would like to see a study done on various swing speeds including tour level speed and see if there is a point of dr.

    • Matt Saternus

      Bob,

      That’s interesting. When you did that head to head test, was it the ball speed that was leading to the difference in distance or launch and spin?

      -Matt

  2. Matt:
    Can you explain the benefit or disadvantage of having or not having an offset. I do not know if not having an offset for these irons is a plus or minus.

    Thanks

  3. Frank Schmieder

    Frank, Bob’s comment sounds as if it defies the laws of physics. It can only happen if the face of the club is decompressing at the moment of impact thetef reducing the ball compression. Usually speed kills .

  4. Man I love the look of these irons. When you say you probably wouldn’t recommend these for high handicappers, about what range of hcp are you referring to, and were you referring to the Hot Metal Pro only or also the regular Hot Metals?

    Thanks!!

    • Matt Saternus

      Ryan,

      This review was strictly about the Hot Metal Pro. I think for a player with a handicap much over 20, there are better options.

      -Matt

  5. paul schofield

    How will combining sets effect the trade in value

  6. Thanks for your review. I read your PXG 0211 review and that’s what I currently play. How would you compare the HMP to the 0211 as far as feel, forgiveness, and distance?

    • Matt Saternus

      Brent,

      I think the 0211 is marginally more forgiving for ball speed. Distance is going to depend on fit and shaft.

      Best,

      Matt

  7. Clayton Malinich

    Hi Matt,

    I am torn on the JPX 921 HotMetal and Ben Hogan Edge irons. I’ve been dead set on the Hogans for a while. However, I did a fitting and got fitted for the 921s and hit them pretty well. I did the demo program for the hogans before the fitting and liked those as well. I wasn’t able to get numerical feedback with the hogans as I didn’t hit them in the simulator. In your opinion, is it worth it to pay the extra $300 or so for the 921’s?

  8. Dane McNamara

    Matt, 70 year old 6 handicapper looking for new irons. Currently have AP3’s which I don’t like and don’t find particularly forgiving. Looking at the 921 HMP’s but concerned with spin nos. I do like the Ping I210’s and plan to hit them soon. It seems to me the 210’s will be a better fit for me with the power spec lofts. Appreciate any feedback you can provide.
    regards,
    Dane

    • Matt Saternus

      Dane,

      I like the PING i210 irons a lot. As far as feedback for you, I would recommend getting a fitting and trusting what you see in the fitting.

      Best,

      Matt

  9. Matt,
    I just got fitted for the HMPs and loved the way they felt. The spin numbers compared to my current set (Bridgestone J33 combo) were astronomically different. The J33 7 iron was producing 9300 rpm while the Mizuno HMP 7 iron was around 6500. The flight, speed and feel were WAY better in the HMPs. I understand that that the irons I am currently playing are ancient in terms of technology, but I’m guessing that I am going to see a remarkable difference as far as where my golf ball ends up distance wise and directionally with that much less spin. The height was very similar as well as the descent numbers. The differences, albeit vastly different, were carry, ball speed and spin (all for the better). I also understand that the Mizuno is 3 degrees stronger than my J33s. Do you think these would be a good buy?

  10. Matt – I got fit and these were the winners. Not sure I want to buy new. How do these stack up against previous year versions? What concerns should I have if I buy used ones if I can find the shafts I need. Thanks!

  11. Hi. How would you compare the Mizuno JPX921 Forged or HMP to the p790s?

    Currently gaming p790s and a noob on Mizunos but want to make a shift soon. Thank you in advance.

  12. I have a high handicap really only because i laid off for a few years. I hit these the other day and was fitted with an XS Shaft Nippon Modus – Medium Grip and had a ball speed on the 7 iron of around 124 with a carry of right at 200. I need something with a good spin rate (what i was told) that will STOP when/if I hit a green. I was also looking at the Ping G425’s…sorry to all the pro’s here for my ignorance, but i am looking for some good advice and need help. I really enjoyed these but want to know other options even if it’s a previous years model. I am 52, so not getting any younger and would love to enjoy the game again. I really didn’t want to break the bank and/or wait for a special order but who knows.

    • Matt Saternus

      Chuck,

      I’m not clear on what you’re asking. Are you looking for other iron models that will spin more? Shaft recommendations?

      Best,

      Matt

  13. Wow, first I am so impressed with you for answering so quick. I guess both…I’m sorry, pleading ignorance, would you recommend a more forgiving set? Yes. Please on whatever recommendation you can offer. My distance is ok in whatever club i seem to hit, i just need it to stop when it lands. Apologies to all others to my ignorance.

    • Matt Saternus

      Chuck,

      No need to apologize at all, we’re all here to learn from each other.
      If you’re looking for a set that’s more forgiving than the Hot Metal Pro but similar in size, maybe even a little smaller, I’d suggest the PING G425. That should also be a good choice for getting a better landing angle. If you want to try something a model older, the G410 is excellent, too.

      Best,

      Matt

  14. Sorry, doesn’t have to be something NEW if a previous years Brand, Model could be a better club.

  15. Thank you very much for your assistance

  16. Hi Matt,

    I used to be a scratch golfer and have taken a break. I figured my blades didn’t match my game anymore once I came back to the beautiful game, and got fitted. I am now a 6 handicap or so, averaging in the high 70s. I was fitted to a Gold Dynamic X100, and was recommended to pair that with either the JPX HM PRO or the Titleist T100s. I am obviously hoping to improve as I get back to form but don’t expect to have the practice time to strike it as consistently as I used to. My RPM was near 7k with the T100s and closer to 6k with the HM Pro. I’m not sure if its just a hit to my pride to get game improvement irons or if I’m justified in worrying that I might soon outgrow these irons. However, the mix of forgiveness/consistency combined with the lack offset (which seemed to allow workability, I like to work the ball with a draw or fade on nearly every shot) seems like a decent fit to the game I’ll likely have for the next few years. Anyway, I really appreciated your article and saw that you were very helpful in providing advice in the comments. Do you have any thoughts for me between these two iron sets? Any advice is appreciated. Thanks, Matthew

    • Matt Saternus

      Matthew,

      I’m very interested in your fitter’s recommendation because, as you allude to, the JPX HMP is much more game improvement than the T100.
      It seems you’re stuck in that eternal conundrum of “Do I buy for the game I have or the game I think I’ll have (or want to have)?” It sounds like you are very realistic about your practice time and ability to improve, but I’m also sensing that you want the T100 more than you want the Mizuno.
      As a 6 handicap, you have plenty of game for the T100 irons. If that’s what your heart wants, get them. If you get the Mizunos but don’t want them, even if you play well with them, you’ll be thinking about the clubs you really want. Ultimately, you’re not playing for a living, so play the clubs that make you happy.

      Best,

      Matt

  17. Aron Bagatta

    Hi Matt. I’m a 55 year old 9 handicapper who currently plays Ping G400 irons with graphite shafts. I hit my 7 iron about 160 and my pitching wedge about 120. I’m looking for a new set that will give me a bit more distance and accuracy. I like the weight of my Pings but feel that the heads are quite large and clunky. I have a budget of about 1200.00 dollars. Any suggestions?

    • Matt Saternus

      Aron,

      I would strongly recommend getting a fitting. That’s the only way to ensure that you’re going to get more performance when you buy that new set.

      Best,

      Matt

  18. Hi Matt,
    I am 71 with a current handicap of 13. I play with Callaway Apex irons with the Recoil es 780 f4 graphic shaft. For the past two years I have more mishits and it seem I really have to jump on it to get my normal distance (150-160 7 iron). On a windy day it balloons and I get less distance. I am considering Mizuno Hot Metal Pro. I’m also considering nippon 105 or 950 steel shaft. Please give me your opinion on switching or alternate options i should consider.

    • Matt Saternus

      Willie,

      My recommendation would be to get a good fitting for both the shaft and club head. Bring your current gamers and let them show you if new clubs can give you the performance you’re looking for.

      Best,

      Matt

  19. How does offset on my irons effect my golf swing?

  20. Matt, I am 73 with a 7 handicap. I have been using Mizuno irons for many years – current Mizuno 919 Hot Metal Pro. Do you think upgrading to the Mizuno 921 Hot Metal Prius worthwhile. Thanks

    • Matt Saternus

      John,

      If you’re looking for a noticeable performance upgrade, absolutely not. At most, you’ll see a small impact in launch monitor numbers. The only exception would be if the 921 is a much better fit for some reason.

      Best,

      Matt

  21. Phil brunt

    Hello Matt, I’m looking at a second hand set of JPX921 hot metal pro and I’m off around the 20 mark, not sure if they are forgiving enough for me. Stiff graphite shaft. But a good price

    • Matt Saternus

      Phil,

      I always advise players to hit the clubs they’re considering before spending their money.

      Best,

      Matt

  22. Matt, late to this party but enjoy your reviews, particularly this one.. For the first time in 30 years, playing something other than a blade w/DGS300 – these HMPs w/Modus 105 S. I know some mishits now make it onto the green, the feedback is OK, but not the purity feel of a good swing. So I wrestle with saving a shot here and there vs the whole blade mindset. I hit it high so the lower spin and stronger lofts aren’t much of an issue. I’m a 4 hcp. I guess it boils down to what one gets from either choice? Ever commented on this before?

    • Matt Saternus

      Jim,

      Thank you.
      It seems you’re struggling with the question of what you’re playing for. If the final score is the ultimate thing for you, it seems that you know the answer is playing a more forgiving iron. However, if you’d rather enjoy the feeling of playing blades, you should switch back. The only bad choice, in my opinion, is trying to split the difference.

      Best,

      Matt

  23. thank you for the tremendous work you do. My question is, with the fairly large and rounded soles, can one get under the ball in tight lies? I have Titleist C16’s, and that’s my main problem with them.

    • Matt Saternus

      Chip,

      If you are struggling with larger, rounded soles, I would probably not recommend this iron.

      Best,

      Matt

  24. Matt, thanks for the review. I got fitted for JPX 921 Pro. TT 105 S300. No doubt they are long. They come off hot and fly high. That being said I can’t get my ProV1 to stop. I’m frustrated with this because I hit my spot and they roll off the green. I went back to my TZoid Pro R300 and my ball stops cold. I went to the 921s because I was excited about the length as I’m now 51. It’s fun to keep up with the young guys but struggling with stopping my ball. Is this common with these irons. I feel like I’m ready to sell them and get the MP 20 MB. Since they come in stronger lofts as an option I might go that route. Are you hearing anyone struggling with consistency in stopping their ball?

    • Matt Saternus

      Albert,

      Yes, this is quite common. The problem with many distance irons is that they get that distance by cutting spin. This can be ok to a point, but, as you’re experiencing, spin is necessary to stop the golf ball.
      I don’t mean to cast aspersions or jump to conclusions, but it seems like your fitting was too focused on distance rather than playability. Depending on where you were fit, you may be able to go back and have them modify the irons or rebuild them with a better shaft so you can get some distance but also hold greens.

      Best,

      Matt

  25. Bill Kretsinger

    Hi Matt, I have the new JPX HMP’s irons 6-LW with the matching 4 and 5 hybrids with the steelfiber shafts. I love the irons but not the hybrids. i plan on replacing the 5 hybrid with a 5 iron. should I stay with the HMP for the 5 iron or go with the regular Hot Metal 5 iron?

    • Matt Saternus

      Bill,

      If you want more offset in the 5I, go with the Hot Metal. If you want the 5I to look like the 6I, get the Hot Metal Pro.

      -Matt

  26. I just bought a set (4-GW) of 921 Hot Metal pros. Got them on from a major seller on Ebay and he said they were mint. They are WAY better than that. Virtually like new. Played my first round with them yesterday and shot an easy 81. I am 76 years old, play to about an 8. Hit 7 iron about 145-150 but had lost perhaps a half club with other stuff. Picked it all back up with these. Solid 180-185 4 iron. EXTREMELY easy to hit and feel buttery smooth at impact…almost forged like feel. 5.5 LZ Black shafts. I will be playing these for years.

  27. Another ignorant golfer needing advice here. I tested several game improvement irons and the HM Pro was the resounding winner on every measure – except spin which dropped alarmingly, right down to 3500 with 7 iron (from circa 6000). Pro was baffled but as ball was flying equally high with all clubs. He videod me in slow mo’ and came to the conclusion that I was grounding the club much earlier with the HMPro and that this was tricking the tracker? Hmmm? Wasn’t convinced. I really liked theses irons but don’t want to be running through the green. What do you think of this issue and the explanation provided?

    • Matt Saternus

      John,

      Very interesting. Couple questions:
      1) What launch monitor were you using? Indoor or outdoor?
      2) How much did the spin drop from the other irons? Were the others at 6000 then the HM Pro was at 3500 or was it more like 4500 to 3500?

      Best,

      Matt

  28. Thanks for the response.
    Sorry can’t help with the launch monitor but was outside.
    Spin dropped from circa 6000 with other clubs (T300, Apex DCB etc) to circa 3500 with HM Pro.
    Sorry , not giving you much to go on here.

    • Matt Saternus

      John,

      If it was outdoors, the type of launch monitor is less of an issue.
      Assuming that you hit more than just a couple balls, that’s a very concerning spin reduction. I would not play an iron with spin that low.

      Best,

      Matt

  29. Good review. My one comment is that they are still a little chunky at address. I can see better players not liking them at address. I’m a 8 handicap and just did an iron fitting; the Mizuno 921 HM Pros we’re the best club for me – by far. My 7 iron carry averaged 205 and they beat out the TM 790, srixon sx7, cobra Kings, titleist t100, and callaway rogue ST. Longer, straighter, better spin numbers, better launch and decent angles…I was blown away. Don’t let the “game improvement” category scare any of the players away, these things are for real.

  30. Hi Matt,
    I can get Mizuno HM irons with the recoil 95 F4, a shaft I know from past experience is a good fit, with no up charge.

    OEMs are going to ES780s as standard offerings, a shaft I tried once that was too light for me. Mizuno and Srixon are the only brands I know of with recoil 95s in their fitting cart, however, Srixons will be $400 more.

    My miss is a left overcooked draw, 8 HC, so the lower offset HM Pro looks like a perfect candidate without getting into a huge up-charge on shafts. I’m going to a Mizuno fitting this week.

    Can you think of anything else similar where I can get the heavier recoil without a huge up charge? Am I missing anything? Thanks.

    • Matt Saternus

      Robert,

      My knowledge of which OEMs offer which shaft stock is limited as I no longer work in retail. It sounds like you’ve found a cost-effective solution for yourself.

      Best,

      Matt

  31. Mike Valles

    I play Mizuno MP60 irons stiff steel shaft now. Looking at 921 HMP. Would the Black 5.5 shafts compared to my steel shafts make a big difference or hould i stick with the 6.0 shafts? I am a 12 hcp. Thanks

    • Matt Saternus

      Mike,

      Moving up or down a flex can have a significant impact. My advice is always to get fit before buying any clubs.

      Best,

      Matt

  32. Mike Valles

    How are the 5.5 Black steel shafts?

  33. 18 hcp, which would be better?
    HM or HMP?
    Also would I benefit from these clubs?
    Thanks

    • Matt Saternus

      Don,

      My advice is always to get a fitting. You will get your own data to see if you benefit from new clubs and how much.

      Best,

      Matt

  34. Nick schuka

    Hi Matt, in your option and all reviews is there much difference in improvements of irons from model to model and is it worth the money I feel aMizuno is a mizuno and speaks for itself and a very good quality product and can’t beat their forging process compared to other countries what line of jpx irons were the better set since introduction?

    • Matt Saternus

      Nick,

      From one year to the next, there is rarely a large change in performance/quality. However, as you get two, three, four years between models, those benefits add up and become more meaningful.

      -Matt

  35. Heath Barney

    I’ve only been playing and hitting the range seriously for around 3 months now. I’ve been playing with some 20-something year old hand me downs and have managed to be scoring in the 105-115 range. I went to get fitted for some irons that I can learn with and grow into. My fitter had me swinging the JPX HMP. With the 7i I was getting club head speed around 95mph and carrying around 180yds. There were other clubs that were more forgiving and I was hitting further, but he said he likes the JPX HMP for me because he’s afraid I would out grow out of those other clubs too quickly and need to be shopping again sooner that later. I guess my question is should I count on improving and being able to play these, or should I go with something more forgiving that might could hold me back later?

    • Matt Saternus

      Heath,

      I’d offer two thoughts.
      First, I think the idea of “growing out of clubs” is one of the most overstated things in golf. Guys have won on Tour with SGI irons. Are there things about “players” clubs that are helpful for single digit players? Sure, but the “need” to “upgrade” is about ego more than game.
      Second, with regard to “will you improve” you are the only one who knows your desire and your life circumstance. If you don’t have time to practice, you probably won’t get much better. That said, you have a lot of speed which hints at good athleticism, so my guess is that you have a lot of room to improve your game.

      Best,

      Matt

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